Director Roman Polanski faces more time in jail after his legal team asked a Swiss court to release him and were told a decision could take weeks.
Polanski is being held in Switzerland on a US arrest warrant over his conviction, 30 years ago, for unlawful sex with a 13-year-old girl.
It is not clear why legal proceedings have been made now.
But on Tuesday, US prosecutors claimed the 76-year-old had been on an Interpol "wanted list" for years.
Polanski's agent, Jeff Berg, said the arrest made "no sense" as he had travelled extensively across Europe.
But US authorities implied the filmmaker had been adept at evading arrest.
"The idea that we have known where he is and we could have gotten him anytime, that just isn't the case," said Chief Inspector of the US Marshals Service Thomas Hession.
He said the 76-year-old Polish director had been on "red notice" by Interpol, alerting other countries that the US was seeking extradition.
But he said proper legal channels had to be followed, which meant they had to know Polanski's specific whereabouts before a country could be asked to act.
Speaking to news agency The Associated Press, Swiss Justice Ministry spokesman Guido Balmer said: "We will examine the ruling and then decide what we will do."
Polanski's agent on extradition fight
He refused to speculate on how long Polanski would remain in jail.
However, experts say that even if the Swiss Federal Criminal Court rules in Polanski's favour, the decision would probably be appealed immediately by the Swiss government.
That would mean the director's incarceration in Zurich would be extended.
Previously, Los Angeles deputy district attorney Richard Doyle had stated in court testimony: "He knows where he can go. He knows where he can't go. He's been a careful man all these years."
But Mr Berg said: "How hard would it be to find someone shooting a major film in a European country?
"He travels with transparency across Europe. It makes no sense."
According to the Associated Press, the Swiss Criminal Court has said Polanski's lawyers have requested the film-maker's release but precedent in Swiss law shows that the subjects of extradition requests are normally kept in detention.
He is being held in Zurich, where he has been allowed to meet his wife, French actress Emmanuelle Seigner, as well as lawyers.
Post-production work on Polanski's latest film, The Ghost, starring Pierce Brosnan and Ewan McGregor, has been halted.
Mr Berg said that, while editing had been completed, there was still work to do on the music score and other post-production details.
Meanwhile, a petition circulating in France, where the director has made his home, has drawn support from film-makers including Pedro Almodovar, Stephen Frears and The Pianist writer Ronald Harwood.
Polanski pleaded guilty to unlawful sex with an under-age girl following a plea bargain. He had originally been charged with six offences including rape and sodomy.
Polanski's wife Emmanuelle Seigner has been allowed to visit him in jail
But he fled the US before he could be sentenced and has not returned to the country since.
In the past year, his legal team has had a request turned down to have a hearing on the rape charge heard outside the US.
Lawyers are trying to get the case dismissed on the grounds that the original trial was the subject of "judicial and prosecutorial misconduct".
The victim at the centre of the case, Samantha Geimer, has previously asked for the charges to be dropped. She has already sued Polanski and reached an undisclosed settlement.
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